Today is Data Privacy Day, a global initiative to highlight information security rights and practices, especially among teens, professionals, corporations, and the government.

As part of the celebration, TUAW (along with our sister blog Download Squad) has seven good ideas for you about how to keep your data safe and away from prying eyes with Mac OS X Leopard. Also, be sure to browse TUAW articles filed under Security for other tips and alerts about keeping your data safe.

1: Turn on your firewall

Leopard, as we all know, comes with a built in firewall to prevent other computers from connecting to internet-facing ports on your computer. But: Did you know it's turned off by default?

To turn on your firewall, open System Preferences, and click the Security icon. Then, click the Firewall tab. Make sure either "Allow only essential services" is selected, or you can choose to "set access for specific services and applications" yourself.

You can also use "Stealth Mode": when enabled, computers that send data to blocked ports won't even get acknowledgement that the data was received. To enable Stealth Mode, click the Advanced button on the Firewall tab of the Security preference pane, and click the check box next to "Enable Stealth Mode."

2: Set a screen saver password

A feature popular with Windows users, Mac OS X can also lock your screen when your computer sleeps or when the screen saver comes on. Simply open System Preferences, select Security, and choose the General tab. Click the check box next to "require password to wake this computer from sleep or screen saver," and you're all set.

If you have automatic login enabled and click the "require password" check box, Mac OS X will recommend that you disable automatic login. This means you'll have to enter your password to turn your computer on, too; nefarious nogoodniks won't be able to restart your Mac while the screen saver is on to circumvent the need for a password. Good thinking.

Danny Gorog at APC Magazine has written a really nice analysis of something that's rather strange when you think about it -- why aren't there any high definition DVD drives on Macs yet? It has been asked for by a few folks, but by and large, Apple has pretty much ignored the whole high definition debate. And even now, when we supposedly have a winner in Blu-ray, Apple hasn't pulled the trigger, and consumers, as Gorog notes, haven't even really cared much.

In fact, across the entire PC market there's not a lot of wholehearted support for Blu-ray or any major high definition formats. It's not that DVDs are "good enough" -- HDTVs are selling by the truckloads -- it's more that consumers, apparently, just don't want to settle on another format. And that may be the key to this whole thing -- Apple has a vested interest in selling content, and implementing some other content producer's format into their machines will take away from their best HD content channel yet: iTunes.

And customers, happy to not have to buy yet another permanent format of their favorite movies, may be satisfied with having no next-generation disc format. I, like many users, have already watched tons of HD video without ever having bought a Blu-ray disc. If Apple doesn't need the drives to deliver the same quality content, why should they bother?

In another move by a major player to negate this ridiculous next-gen DVD format war, Think Secret is reporting they have evidence that Apple might very well support both Blu-ray and HD-DVD with their upcoming Mac OS X 10.5 Leopard release. This is an interesting (and wholly welcomed) move from Apple in part because they're on the board of the Blu-ray Disc Association, while others like Microsoft, Toshiba and (strangely) Intel are camping out on the HD-DVD side of the fence.

It would be great to see this rumor come true, as the last thing users need is another headache-inducing, hardware-stratifying format war to both up their daily computing.

Engadget HD linked a theory from Robert X. Cringely as to why Apple hasn't included Blu-ray drives in any of their Macs yet (it isn't even an option in the Mac Pro), despite being on the board of the Blu-ray Disc Association. Mr. Cringely more or less links the lack of Blu-ray in Macs to movies and Apple's strategy with downloadable iTS content and the upcoming iTV. The thinking goes: if Apple can sell you a downloadable movie through the iTS and an iTV on which to watch it - why undercut that model with a Blu-ray drive built right into the machine?

I disagree. There's plenty of other uses and potential (heck, they can hold up to 50GB) in these warring next generation optical formats (Blu-ray and their mortal enemy, HD-DVD), and that's exactly the point: these formats are in the middle of an industry polarizing war, and I think Apple hasn't committed to including either in their machines because they don't want risk leaving their customers high and dry once the dust settles and (dear lord, finally) one format wins out. The iTS/movie downloads/iTV theory doesn't hold water in my book also because that would mean they should eliminate CD and DVD drives from their machines - after all, those drives can undercut their iTunes Store music and movie purchases, right? These discs can hold a lot more than simple movies.

This ridiculous Blu-ray/HD-DVD situation is Betamax vs. VHS all over again, and while Apple is known for pushing the envelope on which technologies they adopt, I believe they're simply waiting for an actual standard to emerge. The only question is when these camps are going to get over themselves and stop forcing consumers to stock up on Advil for every trip to the electronics store.

VisualHub is a feature-packed and 'universal' video converter for Mac OS X from the maker of iSquint. From its website: "VisualHub bridges the gap between numerous complicated video formatting standards, and people that just want to get the job done - just what you would expect from the Mac." It boasts fast conversion from nearly every video format to iPod, PSP, DV, DVD, AVI, MP4, WMV, MPEG and Flash (what: no animated GIF?), and brags about ts three-step conversion process: click, drag, click.

Fortunately, VisualHub also offers advanced features like bitrate control, frame cropping and audio quality. Xgrid is supported for those with multiple Macs on a network and CPU cycles to spare, while QuickTime Pro and other plugins need not apply.

VisualHub's long list of features don't stop there, however, so check out Techspansion's product page for the full feature list and samples of its work. A demo is available, while a full license will cost you a mere $23.32 USD.

[thanks Khaled!]

For Intel Mac users who either love or hate WMV but have to deal with it one way or another, Flip4Mac has just begun beta testing the long-awaited Universal Binary version of their WMV QuickTime components. Announced in their forums today, it is more or less an invite-yourself program, as I had to contact them weeks ago to get on their email announcement list.

After briefly testing on my MacBook Pro, it seems like everything is working just fine. I'm able to play embedded WMV files with no problem, but I unfortunately don't have any locally saved WMV's to try at the moment. So far, the beta seems like a success, and while I hate the WMV format just as much as the next Mac user, it's nice to no longer receive that 'plug-in not found' error.

John Gruber pointed to a post at the Ars Technica journals by Ken Fisher (their editor-in-chief) in which he reminds everyone that AAC isn't 'Apple's format'. This is in response to all the recent buzz and speculation of Sony's announcement of AAC support; it appears that many took this as some sort of a bow to Apple's dominance.

Ken was refuting this speculation because he doesn't see it as enabling Sony to get a one-up on Apple - after all, their devices still can't play DRM'ed music from the iTMS. I think he's only partially right though. To be clear: I don't think supporting AAC will help Sony to dethrone Apple's dominance in the digital music player market anytime this millenia, but it certainly could boost their sales to all sorts of individuals who who might prefer the iTunes experience, or want to own more than one device, share libraries - you get the idea.

iTunes, the iTMS and the iPod are such a huge hit because they're all incredibly well designed and so darn easy to use. Apple's controversial philosophy of controlling both the hardware and the software has hit one out of the park - and then some. However, plenty of statistics on the number of iTMS songs per iPod can be found everywhere, and the numbers aren't amazing. I've seen everything from 5 on the low end up to 25 on the high, and I'd bet that, on average, even the newest of new iPod owners easily has far more music stuffed into their iPod by day two. Granted, a lot of people are illegally downloading a lot of their music, but they're also making that music themselves by ripping CDs from their own collection and their friends'. And what format do you suppose is the default for ripping music in iTunes? Hint: it isn't MP3. Sure, AAC isn't 'Apple's format', but the company sure is AAC's biggest pimp.

This is the music that Sony is going after. They're betting that by (finally) supporting MP3 and now AAC, their devices can play what is arguably *most* of the music that users have cataloged in iTunes. While I love the iTMS as much as the next customer (I've purchased over 520 songs from it), Sony simply doesn't need to care about not being able to play FairPlay tracks because, by comparison, there just aren't that many of them. Apple doesn't want to open their system to other manufacturers, and they don't have to - other manufacturers are (legally) coming to play in Apple's sandbox, which is mostly made up of music that is not from the iTMS.

With moves like this from major companies like Sony, I'm wondering how soon we can start declaring this market a win for Apple, but also a win for companies who can become big niche players. My Sony Ericsson Walkman phone, for example, can play AAC music and hold more than a 1 GB nano (yes - oddly, other Sony-related devices, like some of their phones, have supported AAC for a while now). And it can make phone calls. And take 2 megapixel pictures. Sure, its interface makes me want to cry, but that's why I mainly use its music abilities when I work out so I don't have to risk bouncing around the hard drive in my iPod like a pinball machine when I run.

Sony's support of AAC sure won't replace a lot of iPods, but it can offer many consumers a choice in devices for some of the other uses in their life.